Magneto-electric ignition apparatus



Oct. 25, 1932. BURST 1,883,885

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Patented Oct. 25, 1932 UNITED STATES PATENT OFFICE ERNST DURST, OF STU'TTGART, GERMANY, ASSIGNOR TO ROBERT BOSCH- .AKTIENGESELLSCHAFT, OF STUTTGART, GERMANY MAGNETO-ELECTRIC IGNITION APPARATUS Application filed November 30, 1931, Serial No. 578,143, and in Germany December 9, 1930.

The invention relates to magneto-electric ignition apparatus suitable for use with i11- ternal combustion engines and of the type having a rotating magnet and a stationary armature. In order to render the effect of armature reaction negligible to the magnet, it is already known to make the pole shoes extend so far round the armature that they almost touch each other and so form a magnetic shunt for the path of the lines of force through the armature. In the case of stationary armatures built up of stamped metal 1 sheets for ignition apparatus having a rotary magnet, the long extensions of the pole shoes usually entail a large Waste of sheet metal.

This is avoided according to the invention by providing a bridge of magnetic material being arranged between the shanks of the armatitre.

An example of construction of the invention is illustrated in the drawing, in which Figure 1 is a sectional view of a magneto ignition apparatus.

Figure 2 a section on the line A-A of Figure 1.

In the drawing, a is the rotating permanent magnet and b are its pole shoes. The stationary armature consists of two shanks (1, provided with pole shoes 0, which in known manner are incast in the casing e of the ignition apparatus. The ends of the shanks projecting from the casing are bridged by the core 7, which carries the coil 9. In the free space between the rotor a and the coil 9 a magnetic shunt 1', consisting of sheet metal strips, is incast with the inner walls h of thecas ng which embrace the armature shanks cl, so that its ends 1: are spaced a small distance away from the shanks d,'.which space'is occupied by the non-magnetic material of the casing. The amount of this spacing will determine the action of. the shunt( The bridge 71 may also be arranged on the side of the armature pole shoe facing the magnet rotor, or it may be arranged on both sides of the rotor. i

I declare. that what'I claim is: 1

1. A magneto including in combination a rotating permanent magnet, stationary pole shoes forming an armature, an armature winding thereon, and a magnetic shunt between said pole shoes;

2. A magneto including in combination a rotating permanent magnet, a non-magnetic armature casing, magnetic pole shoes incast therein, an armature winding on said pole shoes, and a magnetic shunt between said pole shoes.

3. A magneto including.in combination a rotating permanent magnet, a non-magnetic armature casing, magnetic pole shoes incast therein, a bridgeconnecting said pole shoes, an armature winding on said bridge, and a magnetic shunt between said pole shoes incast in said casing. 1

4. A magneto including in combination a rotating permanent magnet, a non-magnetic armature casing, magnetic pole shoes incast therein, a bridge connecting said pole shoes, an armature winding on said bridge, a magnetic shunt between said pole shoes incast in said casing and shorter than the spacing between said pole shoes.

5. A magneto including in combination a rotating permanent magnet, a non-magnetic armature casing, magnetic pole shoes incast therein, an armature winding on said pole shoes, and a laminated magnetic shunt between said pole shoes.

6. A magneto including in combination a rotating permanent magnet, a non-magnetic armature casing, magnetic. pole shoes incast therein, a bridge connecting said pole shoes, an armature winding on said bridge, and a magnetic shunt between said pole shoes incast in said casing in a plane parallel to the axis of rotation of said permanent magnet.

In testimony whereof I have hereunto affixed my signature.

ERNST DURST. 

